Optical property of nanoparticles with a dielectric core and a metallic shell

Abstract

Plasmonic nanofluids have attracted great attention in solar energy harvest due to its advantage of high absorption efficiency at resonance wavelength caused by localized surface plasmon resonance (LSPR). However, the new issue is how to realize broadband absorption along the whole solar spectrum. Two approaches to resolve this issue is to blend nanoparticles with different resonance wavelength or to find structures with multiple resonances along the solar spectrum. Researchers have tried different materials and different shapes for nanoparticles. In this work, three new shapes of nanoparticles are investigated and their optical property (absorption efficiency) is calculated. These three nanoparticles are all composed of a dielectric core and a metallic shell. The shapes of the core are rod, prism, and star respectively. Different parameters including core size and the shell thickness are studied to explore their effect on the optical property of the nanoparticles. The boundary element method is applied for this numerical study. Results show that the parameters are able to tune the optical property effectively, including number of absorption peaks, resonance wavelength and strength. Thus these three nanoparticles can be good candidates for designing plasmonic nanofluids for solar energy harvest.